Re: [Qemu-devel] [PATCH 1/2] trace: Add "cpu_init" event

[Lluís Vilanova]

Stefan Hajnoczi writes:

> On Tue, Sep 06, 2016 at 04:25:53PM +0200, Lluís Vilanova wrote:
>> +## vCPU
>> +
>> +# Create a new virtual (guest) CPU
>> +#
>> +# Targets: all
>> +guest_cpu_init(void *cpu) "cpu=%p"

> This isn't a vcpu trace event.  Please add keep it with the other
> non-vcpu trace events:

> # cpus.c
> guest_cpu_init(void *cpu) "cpu=%p"

It actually is, but as the commit message says, declaring it as such prevents
the event to be emitted.

The culprit of this problem is that new vCPUs start with an empty per-vCPU trace
event set. Should we make vCPUs "inherit" the state from the global state?
(i.e., if any vcpu event is set on any vCPU, set it on the new one). The next
question would then be, should this inheritance only apply until tracing is
fully initialized of for the whole duration of QEMU?

Cheers,
  Lluis